I have both an Essence and a Stanley Clarke Sig Std. My rig is an F1-X, SF-2, QSC 1804 into Ampeg BXT Cabs (2X10, 1X15, and 4X10), and I also have a Mesa Boogie Walkabout Scout Combo (12 speaker) and a Phil Jones Bass Briefcase.
What I've found with the Essence and the SC Sig Standard is that I set the bass, treble and mids on the amps fairly equal (either boosted or cut) and use the eq on the bass to even things out. In other words, I dial in a tone I like, then tweak it from the bass itself. This is one of the things I like about Essence/Sig electronics - they're simple to use, and easy to dial things in. Same goes for my Series II, as I tend to boost the CVQ all the way, and only deal with the filters as tone modifiers.
For me, on the Essence, I use the pan pot about half way back towards the bridge pickup, and roll off the filter as needed for certain tones. On the SC Sig Std, I have more options, but both Q-Switches remain on, and then I adjust the filters as needed depending on the tune. I'm mostly a finger style player, so this works for me.
If, on the other hand, I'm doing slap, the filters are usually wide open. It gives you that very hi-fi top end you like with slap, IMHO.
As for a pick, I've used the above settings successfully. Of course, only you can be the judge of what works for you.
My suggestion is to experiment and find out the best combination of amp/instrument settings that work for you, and go from there. Hope this helps.
Alan